Process.Start returns null

Question

i am writing a program that launches a random file in a directory. the file can be of any time, but mostly video or image files. each time i launch a file i want to close th

Answer 1

EDIT: Thanks to leppie's comment, I suspect I know the answer: my guess is that you're "starting" something like an image, and it's reusing an existing process to open the document instead of creating a new one.

I've reproduced this with this simple test app:

using System;
using System.Diagnostics;

public class Test
{
    static void Main()
    {
        Process proc = Process.Start("image.tif");
        Console.WriteLine(proc == null);
    }
}

This prints "true" because it's using dllhost.exe to host the Windows Image Viewer, rather than creating a new process.